Identification and interpretation of clinical and quality of life prognostic factors for survival and response to treatment in first-line chemotherapy in advanced breast cancer

The aim of the project was to identify clinical and quality of life (QL) fa ctors that together predict survival and response to chemotherapy in advanc ed breast cancer. Potential prognostic factors were studied in 187 women wi th baseline QL data from a trial of paclitaxel versus doxorubicin as first- line chemotherapy. Demographic and clinical factors studied were age, perfo rmance status, dominant site of disease and preceding disease-free interval (DFI). Factors from the EORTC QLQ-C30 were all Function scales, fatigue, n ausea/vomiting, pain, dyspnoea, insomnia, loss of appetite and global QL. T he proportional hazards regression model with stratification for treatment. and the logistic regression model adjusting for treatment arm were used fo r univariate and multivariate analyses of survival and response to treatmen t, respectively. For survival, multiple sites of visceral disease, pain, gl obal QL and fatigue were significant prognostic factors in the univariate a nalysis. The final multivariate model predicted poor survival with multiple sites of visceral disease (P = 0.003), DFI less than or equal to 2 years ( P = 0.026) and pain (P = 0.003). For response, age, dyspnoea, fatigue and g lobal QL were significant predictive factors in the univariate analysis. Th e final multivariate model for response selected DFI (P = 0.009), multiple sites of visceral disease (P = 0.037) and dyspnoea (P = <0.001) using forwa rd selection, but model instability was indicated by the inclusion of fatig ue and emotional function in the final model when backward selection was us ed. In addition to known clinical factors, patient-assessed QL variables ap pear to be prognostic for survival and response to chemotherapy in women wi th advanced breast cancer. However, identification of prognostic factors fr om responses to questionnaires may be unstable, and their reliability and c linical utility should be tested prospectively. (C) 2000 Elsevier Science L td. All rights reserved.